Question

Why did the 38th parallel lead to the Korean war

Answer 1

the United States and the Soviet Union seen eye to eye but only temporarily to split N Korea at the 38th

Answer 2

After WWII Korea was divided at the 38th parallel for purposes of military occupation. This line then solidified into a political frontier between American-supported Republic of Korea and the Soviet backed Democratic People's Republic of Korea. North Korean troops swept across the 38th parallel to attack South Korea.